The present invention relates generally to security devices, and more particularly to security devices for deterring theft of articles of merchandise displayed for customer handling and demonstration.
Articles of merchandise such as electronic and optical instruments, computers, outer garments and similar portable items are often openly displayed on store shelves and racks in a manner which invites customers to handle and inspect them before deciding to make a purchase. Such items are especially vulnerable to shoplifting. Consequently a panoply of security systems have been proliferated for instantly detecting and alerting store personnel when a theft is in progress. Unfortunately, as quickly as new systems are devised, the more cunning and experienced shoplifters find ways of defeating or neutralizing them. Less defeasible systems are possible, of course, but usually involve initial costs and maintenance expenses disproportionately higher than the value of the goods being protected.
The simplest security measure, short of displaying the goods behind locked glass panels accessible only in the presence of a salesperson, is to tether the goods from a display fixture with a relatively unbreakable chain or flexible wire cable. An improvement on this concept is the Vulcan Pullbox.RTM. manufactured by Vulcan Spring and Manufacturing Company, Telford, Penna. It includes a retractable cable designed especially for point-of-purchase applications where the merchandise can be demonstrated by the salesperson or easily handled by the customer while at the same time the product is held captive to the fixture on which it is displayed. A spring-biased reel provides a retracting force throughout the full extension of the cable to take up any slack which might otherwise entangle with itself or other articles.
Unfortunately, a tethered cable or chain does not thwart the more insolent and brazen shoplifter from cutting the cable or chain. Countermeasures which alert the shopkeeper when this occurs have been used or suggested. For example, U.S. Pat. No. 4,069,919 to Fernbaugh discloses a tether of electrical conductors which complete an alarm circuit. When the circuit is broken, as by cutting the cable, the alarm is energized. U.S. Pat. No. 4,772,878 to Kane, U.S. Pat. No. 4,896,140 to Biever et al, and U.S. Pat. No. 4,616,113 to Jank et al disclose tethers formed of electrical conductors which also sound an alarm if they are electrically shorted in addition to if they are cut. In each of these devices the tether conducts electricity. As a precaution against electrical shock to customers handling the product, they must be carefully insulated and routinely inspected for exposed wires. Electrically conductive tethers are therefore extremely limited in application.
U.S. Pat. No. 4,698,617 to Wilbur discloses a non-electrical tie-down cord which mechanically actuates an electrical switch in a separate alarm circuit when excessive tension is applied to the cord. However, the alarm is not activated if the cord is cut or disconnected.